<!--
 * @Author: your name
 * @Date: 2021-08-20 16:50:24
 * @LastEditTime: 2021-08-20 17:08:53
 * @LastEditors: Please set LastEditors
 * @Description: circle
 * @FilePath: \代码\day04\5-circle.html
-->
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>circle</title>
    <style>
        .outer , .inner {
            box-sizing: border-box;
            /*border-radius大于50%为圆  */
            border-radius: 60%;
        }
        .outer {
            width: 300px;
            height: 300px;
            /* solid表示实线 */
            border: 3px solid #ccc;
            /* 水平居中 */
            margin: 0px auto;
            padding: 50px;
            transition: padding 2s;
        }
        .outer:hover {
            cursor: pointer;
            padding: 10px;
        }
        .inner {
            /* 基于父元素的百分比 */
            width: 100%;
            height: 100%;
            border: 5px solid #ccc;
        }
    </style>
</head>
<body>
    <div class="outer">
        <div class="inner">

        </div>
    </div>
</body>
</html>